Re: Anyone tried SystemTap with the latest RHEL5 Beta refresh

[William Cohen <wcohen at redhat dot com>]

Vara Prasad wrote:
> Frank Ch. Eigler wrote:
>
> > Hi -
> >
> > On Mon, Oct 30, 2006 at 10:27:47AM -0800, Vara Prasad wrote:
> >
> >  
> >
> > > [...]  Badari is playing the role of a customer. His point of view
> > > is, i have stock RHEL 5 setup, i have not made any changes to the
> > > setup and trying to use systemtap and i expect it to have all the
> > > pieces needed [...]
> > >   
> >
> >
> > Unfortunately, other customers prefer that systemtap's loose
> > dependencies (particularly, the kernel-debuginfo) not be installed by
> > default, even if they choose an "install everything" option at the
> > anaconda screens.  Can you think of a way of satisfying both groups?
> >
> > - FChE
> >  
> O.k, before i think of a way to satisfy both the needs i need to 
> understand the objection of the other group.
> The objection of other customers to not to install debuginfo package is 
> it because of wasted disk space due to large size of debuginfo package 
> or time to install or something else.
> I am assuming kernel debuginfo is considered a dependency for SystemTap, 
> am i right.
> What is the point of installing a package that doesn't work due to lack 
> of dependencies? In other words are we not breaking the semantics or 
> meaning of full package install if we don't install required 
> dependencies when the customer chooses a package to install.
>
> bye,
> Vara Prasad

There are cases where one could be using systemtap on a locally-built kernel. 
For this case the kernel-debuginfo dependency does not make sense. This is a 
common use case for kernel engineers.

There are may be more than one kernel installed on the machine. Forcing a 
kernel-debuginfo to be installed doesn't guarantee that it matches with the 
currently running kernel. RPM dependencies only make sense if there is only one 
possible package installed on the system. Kernel rpms violate that rule. For 
Fedora 6 (and RHEL5) there are multiple kernel-debuginfo. Having dependencies on 
all the possible debuginfo because the might be used isn't going to work.

The translator error reporting about the lack of debug information could be 
clearer about what is going on. However, putting in a questional RPM dependency 
in the systemtap package is not going to solve the problem.

-Will